1. Field of the Invention
The present invention relates to a method for detecting color mixing defects, and more particularly, to a method for detecting mixing defects of color channels when displayed on liquid crystal monitors.
2. Description of the Prior Art
The approach of semiconductor technology brings a liquid crystal monitor (LCM) to be a broadly used display device today. However, a ready-made liquid crystal monitor unavoidably includes some defective pixels due to mass-production. Methods for detecting those defective pixels are thus commonly employed before sale. Conventional methods for detecting defects of the liquid crystal monitor must adopt the direct check that displays three independent color channels such as red, green, and blue as described in FIG. 1A. Those conventional methods verify whether or not the tested color channel is defective, as determined by the three independent channels. For example, referring to FIG. 1B, a defective liquid crystal monitor usually shows a plurality of abnormal points that exist on the red, green, and blue channels, respectively.
Conventional methods are limited in that they can only detect defects of a single color channel, but cannot detect defects derived from mixed channels. Typically, a liquid crystal monitor containing errors caused by color mixing usually shows twinkling regions because the defective pixels derived from color mixing are usually continuously flashing or frequently vary their colors. For example, referring to the upper portion of FIG. 3, a girl dressed up in a blue shirt is abnormally depicted because portions of the blue skirt are shown with other colors such as yellow. Unfortunately, adopting the conventional method cannot confirm the above errors. Additional detecting methods are thus required to prevent breakdown products from being sold. A need has therefore arisen for a method for overcoming the above mentioned disadvantages so that defective pixels due to color mixing can be detected.
According to the above objects, the present invention provides a novel method for detecting defects on a liquid crystal monitor when mixed colors among color channels. The disclosed method utilizes the interference of four color channels such as red, green, blue and white colors to check whether the detected liquid crystal monitor can normally show the mixed colors thereon. The embodiment of the present invention is to draw a rectangular drawing on the liquid crystal monitor, wherein the most upper left point, the most upper right point, the most lower left point, and the most lower right point are respectively allocated by red, green, blue, and white pixels. Each color channel then extends separately along the diagonal direction and accompanied with color intensities gradually decreasing to obtain an interference diagram that contains several arc stripes on the rectangular drawing. Accordingly, the rectangular drawing can faithfully display where the abnormal pixels are if any abnormal situation occurs at color mixing. Additionally, information of the embodiment can be further illustrated by using a menu or a display window according to display the mode of a liquid crystal monitor currently used.